1. Field of the Invention
The invention generally relates to athletic shoes and, more specifically, to shoe soles for enhancing gripping with a smooth hard surface.
2. Description of the Prior Art
In the quest to provide and maintain adequate traction, numerous efforts have been made to enhance the coefficient friction between a shoe sole and a surface on which the shoe is used. For example, in U.S. Pat. No. 4,555,765 a sport shoe sole is described that possesses a high coefficient of friction along certain portions of the sole while other portions of the sole are formed of a compressible and resilient material that is harder than the material of the rest of the sole.
Efforts have also been made to coordinate the design of the sole with the anatomic variations of the foot. Thus, in U.S. Pat. No. 7,101,604 a sole is described as having a natural grip corresponding to the ergonomic gripping or traction pattern based on the natural foot print of the foot. The sole design, therefore, is provided with major and minor projections that correspond to the various high or low points of the human foot, presumably corresponding to the points of maximum pressure or compression. However, the sole is formed of an elastic deformable material commonly used for athletic shoes, including rubber, PVC and any suitable synthetic elastic substance. The sole is also described as having a base and projections, recesses and ridges as well as possibly including two or more layers in forming the various contours in a sole. Enhanced gripping is based primarily on the configurations of the various projections, ridges, etc.
Athletic shoes have also been proposed that have interchangeable soles. However, these are primarily intended to replace soles that wear out to avoid the expenses of purchasing new shoes. Such an athletic shoe with an interchangeable sole is described in U.S. Pat. No. 5,317,822. Another shoe having a replaceable sole is described in U.S. Pat. No. 7,331,123, the shoe having a thin cavity in the bottom surface of the sole that releasably receives a thin sole plate. The sidewall of the cavity includes flaps that extend into the cavity and the sole plate has depressions that receive the flaps when the sole plate is placed in the cavity and pushed past the flaps. The design is intended to allow the individuals to select their own personal preferences within a wide range of styles and colors of foot wear.
It has also been proposed to interchange gripping elements on sport shoes. In most of the proposed designs the gripping elements that are designed to be replaced are spikes of the type used on golf, soccer or other sport shoes. For example, in U.S. Pat. No. 3,812,605 a sport shoe is described with interchangeable gripping elements in the form of spikes that are releasably fastened in recesses in a sole by locking pins extending through the soles in the base portions of such spikes. The spikes are rotated a predetermined angle from the original positions to lock or unlock the spikes—similar to a bayonet type connection. A non-slip sandal with fully replaceable parts is described in U.S. Pat. No. 5,836,090 in which the replaceable studs can be attached and disconnected from threaded opening in the sole so a user can select a profile of the spikes, including a short stud, a medium sized steel spike and a long steel spike.
However, none of the known prior art discloses a shoe sole with replaceable gripping pods or shoe soles specifically for enhancing the gripping properties of sport shoes intended to be used on smooth hard floor surfaces such as basketball, volleyball and the like courts.